1. Field of the Invention
The present invention relates to an image recognition method for recognizing an image of a predetermined pattern in an image forming apparatus such as a digital color copying machine.
2. Description of the Related Art
In the prior art, in general, pattern matching is executed for the entirety of a pattern to be detected, with respect to input image data.
As regards a method of detecting a copy-protection mark, Japanese Patent No. 2893080, for instance, discloses a method wherein a plurality of small marks with the same shape are detected from an input image, and a copy-protection mark is determined on the basis of the number of small marks that are present on an outline of a certain figure.
However, in the case of the matching with respect to the entirety of the to-be-detected pattern, if the size of the entire pattern is large, the amount of computations would become enormous.
In the case of counting the number of small marks with the same shape, which are present on the outline of the figure, if the shape of the outline is complex, it is likely that the uniqueness of the to-be-detected pattern cannot be maintained.